Fuel screw adjust - 1981 GSX750E

[Guest]

Im having trouble after carb cleaning. From what I know now, we should never have touched the fuel adjust screw. We have tried to follow a lot of diffrent manuals, but non of them seem to get it running 100%.

Listen to this film, so you can hear what is happening

http://www.youtube.com/watch?v=pQGPPgc5XUE

[subid]

Have you tried this?

Adjusting Idle Mixture on CV carbs, using throttle response method

http://members.dslextreme.com/users/storagecliff1/images/Adjusting_Idle_Mixture_on_CV_Carbs.pdf

[phrode]

Yes, we have. There is slight diffrence, but we can not get running good enough. At 3500 rpm it starts to stall. We have tried with 1/4 turn from 3 1/2 down to 1/2 turn. Does not get any better.

[OldVet66]

I have lost track of what you have done on your bike. Have you adjusted the valves yet?

[phrode]

Yes. Valves is spot on now.

[Nessism]

Is the airbox installed? Sorry, can't view the video since I'm typing at work.

Just for kicks you might want to check the carb rebuild tutorial and Newbie Mistakes threads as linked in my signature to see if anything applies to this problem.

[OldVet66]

Have you checked the tank for rust? If it does, it will continually trash your carburetor rebuild?

[phrode]

subid: Yes we have. No luck.
OldVet66: Yes the valves have been adjusted and are spot on. The tank is clean, no rust in the bowls or fuel filter.
Nessism: The airbox is on. Clean filters, no leaks.


We have rebuilt 2 GSX750E 1981 models. They both have the same problem. In this post you will find my bike http://www.thegsresources.com/_forum...d.php?t=206494 and this post is for the other bike.

We have followed bikecliff's carb manual for cleaning, everything has been done by the book. All is cleaned, all lines, gaskets, o-rings, filters... has been replaced with new ones or checked and cleaned. (this goes for the whole engine). There are no leaks, false air or similar.

They both act the same. We cant figure out what is wrong. No matter how much we tune, it fails at 3500-4000.rpm
We have followed the Clymer manual for everything we have done on the bike, and everything is correct according to the Clymer manual.

[terrylee]

Did you get them synced? terrylee

[phrode]

terrylee: No. they have not been synced. I have read and been told that this problem is not a sync problem. That is why.

[OldVet66]

We have rebuilt 2 GSX750E 1981 models. They both have the same problem

A friend of mine rebuilt two '78 750E's with VM carburetors and had a similar problem. He was very consistent with his mistakes, both bikes were 1 tooth off the marks on the intake cams. Luckily I was able to loosen the cams and fiddle the sprockets one tooth so the match marks lined up. Problem solved. If there is a common thread with both bikes you might want to think of where the same mistake might have been made.